Since 1910, the Smithsonian's National Museum of Natural History has inspired curiosity and learning about the natural world and our place in it.

May 2016

05/27/2016

I am a Museum Specialist in the Department of Botany and the research assistant to curator Jun Wen, whose expertise includes grapes – the plant family Vitaceae, ginseng – the plant family Araliaceae, cherries – the family Rosaceae, and many plant groups found both in eastern Asian and North American that are biogeographically disjunct (species that are related, but separated geographically). Wen is a passionate biogeographer, an inveterate collector of plant specimens, and a strong believer in the collaborative process. Of all the tasks and projects I am given, an opportunity for fieldwork tops the list.

From Left to Right: Zhumei Ren, Sue Lutz and Joe Boggs (Ohio State University) collecting sumac galls in Liberty, Ohio in August 2015.

Recently, I was able to participate in a GGI-funded collecting expedition to study the relationships and geographic patterns of sumacs and mosses in North America. For this particular trip we were joined by Dr. Zhumei Ren, a longtime colleague from China. Ren has been on several collecting trips with me in the past, but this was not our usual plant collecting trip. While we often collect plants that are disjunct species between North America and eastern Asia, we are not usually collecting a plant species that has a 48-million-year-old relationship with an aphid. But that is exactly what we set off to do.

The aphid, Melaphis rhois, has co-evolved with two separate plant hosts integral to its life cycle. The primary host are sumac trees (Rhus); the aphid creates a sumac gall upon which it feeds. Galls are abnormal plant growths caused by the feeding or egg-laying activity of insects. The gall created by the Meaphis aphid is the summer home to a single female aphid where she reproduces for several months. The secondary hosts are the mosses growing in the area. As autumn approaches, the galls are slit open and the aphids fly to the moss beds where they reproduce again and overwinter. In the following spring, the larva feather and fly to the primary host for producing and mating. The mated female will produce a single female baby and the life cycle continues. Interestingly the sumac-gall aphids also show a disjunct distribution with the related aphid group, subtribe Melaphidina, distributed in eastern North America and eastern Asia.

Sumac galls on the leaves of Rhus glabra, collected in Newton Co., Georgia, August 2015.

Our goal on this trip was to collect samples of the unique sumac species in North America over their geographic range in the eastern U.S. in order to conduct more extensive molecular analysis, particularly focusing on the phylogenetic diversity of the species and its disjunction.

While these sumac trees are common, finding trees with sumac galls is a matter of chance. The galls are located on the undersides of the leaf, are globular, and vary in size with the largest about the size of a golf ball. They are often reddish in color, but can also be yellow to light green. We targeted locations that would encompass their geographic range from south to north, but we had a small window of time in which to collect them: when the aphids are mature, but before the galls are open. We needed to rely on first-person reporting to locate each site.

We hit the lottery with Joe Boggs from the Ohio State Extension Service Office. His directions were precise and he met us on site to relate the history of this particular stand of Rhus/gall activity. Boggs departed for the extension office while we continued to collect plant, gall, and moss specimens. As we were packing up our gear Boggs returned. Because Rhus is a member of the Anacardiaceae family (poison ivies and oaks as well), he was concerned that we were exposed to the rash-causing oil, urushiol. He gave us a bottle of poison ivy scrub to remove the oils—good old Midwestern hospitality—and because of this he became the highlight of our trip.

We continued south to Georgia, made a pit stop at the museum to offload specimens and replenish supplies, and continued north to New York, Vermont, and New Hampshire. It was a frantic road trip to make the collections within the prescribed time limit. We successfully collected in every targeted geographic area. But a road trip like this is not without its favorite moments.

Our favorite saying on this trip came from our vehicle GPS guide, when we veered off the preset course – “Take a U-turn (big pause) if possible” – always sounding like it feared a liability.

The collections made from North America will be studied along with many specimens already gathered in China by Zhumei Ren, Jun Wen, and their collaborators to unravel the biogeographic and evolutionary history of this unique group.

05/04/2016

A team of researchers from the Smithsonian Institution and USGS recently spent a month conducting biological surveys in Djibouti (pronounced ‘ji-BOO-tee’), a small country in the Horn of Africa. Djibouti is surrounded by Eritrea, Ethiopia and Somalia with coastlines that abut both the Red Sea and the Gulf of Aden. The country is approximately 23,000 sq. km and ranges in elevation from -155m below sea level to over 2,000 m; making this a potentially interesting place to conduct biodiversity surveys.

This particular trip was the final expedition of a two-part project funded jointly by the U.S. Navy and the Global Genome Initiative (GGI) to survey the flora and fauna and provide the U.S. Navy with information that will be used to create a Natural Resource Management Plan and support the Bird Aircraft Strike Hazard (BASH).

As the Principal Investigator of this project, I had the opportunity to work with mammologists, ornithologists, herpetologists, entomologists, and botanists to complete this task. We spent our days and nights preparing, documenting, observing and photographing as much of the flora and fauna as possible during the spring of 2014 and winter of 2016 with two goals in mind. Firstly, our aim was to help the U.S. military understand the biodiversity of wildlife on Camp Lemonnier (a military base located in the center of the country), and secondly, to provide species information to the Djiboutian Ministry of the Environment.

Prior to our expedition, Parker’s Pygmy Gecko (Tropiocolotes somalicus) was presumed to be rare because it was only known from a few museum specimens. It was the most common lizard we encountered in disturbed second growth habitat, indicating its presumed rarity is a product of the lack of surveys in its limited range rather than true scarcity. (Photo: S. Gotte)

This information will ultimately aid the Djiboutian government in conservation efforts and in designation of critical habitat for protection measures. The specimens and genetic material we gathered will also act as a reference library of potential invasive species that could be unintentionally transported, allowing for faster identification and response to introductions of non-native species.

The Darkling Beetles, a family with more than 20,000 species known worldwide, are a dominant part of the insect fauna in desert regions, and the specialty group of study for Warren Steiner of the Smithsonian Department of Entomology. These flightless Adesmia were conspicuous and common on and around Camp Lemonnier, and active during the day. (Photo collage: W. Steiner)

Our work took us to the nearby shoreline of the Gulf of Aden, to an off-site airfield, and into the rugged mountains of the ecologically unique Day Forest (Forêt du Day). As a result of the two expeditions we now have genetic samples for thousands of insects—now being tested for disease vectors and being used to help describe the insect life; more than 70 species of birds—some documenting new distributional records for the country and providing new resources for world collections; more than 14 mammal species including Speke’s Pectinator and Abyssinian Genet—rare species in museum collections; about 24 species of amphibians and reptiles including Dodson’s toads, Parkers Pygmy Geckos, and a Nubian Spitting Cobra, and several species of highly adaptive plants.

Collected by a variety of sampling techniques and traps, thousands of Djibouti insects and arachnids still await study by many specialists. Based on studies of target taxa so far, nearly all represent new additions to the Smithsonian collections. Ectoparasites were also collected from the many vertebrate specimens and may shed light on local disease vectors. (Photo collage: W. Steiner)

During the most recent expedition to the Day Forest, we traveled for four hours to reach our destination north-east of Djibouti City. This forest is a very special place within Djibouti and only one of two high elevational (1,500 m) closed forests in the country. We stumbled across a large troop of Hamadryas baboons while searching for a glimpse of the endemic and critically endangered bird Djibouti Francolin (Pternistis ochropectus). We were fortunate to have special guests from the local university and the Djiboutian Center for Education and Research Department (CERD) join us in the Day Forest. Two students and two CERD employees eagerly participated in fieldwork activities by assisting the Smithsonian Team with observing the wildlife of the forest.

The Djibouti Francolin (Pternistis ochropectus) is endemic to the high-elevation mountains of Djibouti. This species is critically endangered and restricted to only two areas within the country. (Photo: C. Dove)

Having DNA sequence available in on-line libraries will benefit science in many ways. Potential new species or species range extensions will be identified; genetic information will be available for researchers working in the region; bird DNA sequences will be available for the identification of bird/aircraft collisions in the region; U.S. Navy will have baseline ecological information as they move forward with development of Camp Lemonnier; and information regarding potential conservation of habitat and species diversity will be available to the government of Djibouti.

Rusty Russell (Dept. of Botany) with Apple of Sodom (Calotropis procera). This milkweed relative, originally described from a Middle East collection, extends into the Horn of Arica and throughout the Rift Valley. It can establish itself in the poorest of soils and its dramatic looking fruits are 90% air.

Our trip was a big success, but more biological inventory work is needed in this country to document species diversity and improve knowledge for regional conservation planning. Hopefully, GGI and the Smithsonian will partner with the Djiboutian government for surveys in the future!